This invention relates generally to electric circuit apparatus and, more particularly, to group operated circuit disconnect apparatus for overhead electric power distribution lines carried on poles.
Overhead electric power distribution lines are mounted upon poles by a wide variety of mounting structures. The poles may be 40-50 feet high and the mounting means often carry various distribution apparatus. For instance, the distribution lines require circuit disconnect means at certain locations. Since such distribution lines commonly operate in a three-phase system, there are three associated lines which ordinarily must be disconnected and reconnected simultaneously. This requires group operated switches. Support structures also are mounted intermediate or down on the pole for distribution at certain locations to various facilities remote from the main power line.
Most support structures for mounting the main power distribution lines, take-off lines, group operated switches and other related apparatus comprise elongated cross members secured intermediate their ends to the pole. There is a continuing problem of manufacturing such cross support members in a cost effective manner yet providing sufficient strength to accommodate quite large loads on the distribution lines. The major loading on the support structures comes from the line or conductor loads and is magnified in high wind conditions or during ice storms or the like. Since the support structures actually comprise a load bearing beam, this problem can be further magnified when a line take-off point is located at one end of the beam, for instance. Heretofore, the beam strength of such support structures could accommodate a load of only on the order of 2,000 pounds. This limit often is insufficient and can cause the beam to break or bend, resulting in power outages or, more importantly, dangerous down line conditions.
Another problem with many line support beams is that they are capable of mounting the distribution lines and their associated group operated switches only at selected positions lengthwise of the beam.
This invention is directed to solving these problems by providing a new and improved group operated switching apparatus including a support structure for mounting the distribution lines on a pole, the structure being efficient and inexpensive to manufacture, yet providing a strength not heretofore available. The support structure or beam can mount circuit components at any given location along the beam.